Sawdust and like fine-fuel furnace



1,527,999 A. l. THOMAS SAWDUST AND LIKE. FINE FUEL FURNACE Mar. 3, 1925.

Filed Jan. 1924 2 Sheets-Sheet 1 Alorzza Z 7720/7205,

@ZQM 6M attozwug Mar. 3, 1925. 1,527,999

A. l. THOMAS SAWDUST AND LIKE FINE FUEL FURNACE Filed'J'cn. '7, 1924 2Sheets-Sheet 2 Alan Z0 J Thomas,

aftoz nu Patented Mar: 3, 1925.

PATENT OFFICE.-

.ALONZO IRVEN THOMAS, OF EUREKA, CALHORINIA.

SAW DUST AND LIKE FINE-FUEL FURNACE.

Application filed January 7, 1924. Serial No. 684,759.

To all whomt't may concern:

Be it known that I, ALoNzo I. THOMAS, a citizen of the United States,residing at Eureka, in the county of Humboldt and State of California,have invented certain new and useful Improvements in Sawdust and likeFine-Fuel Furnaces, of which the following is a specification, referencebeing had therein to the accompanying drawings. ThlS 1nvent1on relatesto a furnace primarily intendedfor burning saw dust and other.comminuted wood but also adapted to burn fine and low' grade fuels ofvarious kinds.

One of the largest items of expense in connection with furnaces of thecharacter indicated is that of burned out grate bars. Due

to the closely packed nature of the fuel it is difiicult to get airthrough grate bars of ordinary construction, particularly if the gratebars be close enough together to prevent the fine fuel from fallingthrough. The result is that not only is it difiicult to maintainsufficient air supply to support combustion but, in addition, the gratebars rapidly burn out or become so warped as to render them useless.

In the Patent No. 1,410,141 issued to me on the 21st day of March 1922 Ihave disclosed a construction wherein the saw dust or otherfine fuel isburned upon what is substantially a solid bottom, air being forced intothe fuel from suitable conduits.

In my copending application Serial Number 676,451, filed November 22,1923, I have disclosed a furnace of the same general character as thatillustrated in my patent but wherein certain economies of constructionare brought-about and wherein the air discharging nozzles are bodilyremovable for ready replacement when they are burned out.

The present invention comprlses a furnace of the same general characteras those shown in the patent and application above referred to butwherein the parts are so arranged that nothing about the furnace islikely to burn out. But, if it should burn out, the burned out part maybe readily replaced at a very small cost. 3

The means. by which these objects are achieved are disclosed in theaccompanying drawings wherein through a Fig.1 is a longitudinalsectional view art of a furnace illustrating a preferred orm of theinvention;

Fig. 2 is a transverse sectional view through the furnace of Fig. 1;

Fig. 3 is a longitudinal sectional view illustrating a modified form ofthe inventron.

Fig. 4 is a transverse sectional view ihrough the form of furnaceillustrated in Fig. 5 illustrates a housing of fire-brick or likerefractory material having open sides adapted to receive tuyere ironshereinafter described;

Fig. 6 is a perspective view of a fire-brick hereinafter described; and

' Fig. 7 is a perspective view of a metallic plate constitutin a tuyereiron and adapted for use in the rnace illustrated in I Figs. 3 and 4.

Like numerals designate corresponding parts in all of the figures of thedrawings.

In both forms of the invention, the fur nace comprises a hearth or base5 which may be of concrete or any other suitable materiaL. Formed inthis hearth are a plurality of longitudinally extending ducts. There maybe any number of these ducts and they may be located in varyingpositions with respect to the side walls of the furnace. For

purposes of illustration I have illustrated two inner ducts 6 and twoouter ducts 7. The

two outer ducts are connected by a trans-' verse cross-duct -8 which issupplied with air through a conduit 9 and the two inner ducts aresupplied with air through a conduit 10 which leads to a well 11 which iscommon to both of the inner ducts. Where the base 5 is made: of a cheapand comparatively low grade concrete, I may, if desired, face its uppersurface with a highly heat resisting fire-brick, indicated at 12 thoughI may dispense with this fire-brick and makethe base 5 of any-suitableheat resisting cement.

. In the form of the invention illustrated catedeat alongrth'e edges ofthe ducts 7 v being discharged from the ports as the fuel is'consumed.

By referring to 2 it will'be seenthat the material of the base uponwhiehthe firebrick is supported is notched out as indiand these notched outportions receivethe lower edges of the bricks 16, hereinbeforedescribed. Thus-these notched out portions constitute guides by whichthe bricks are caused to. "lieinj-accurate alignment with each other.and 'without' the necessity for other means for holding them in place.V-

Inth e form of the'invention illustrated in Figs. 3, 4, 5, and'7 theducts 'Z are spanned by' .longitudinally .extendinghousings 17 the sidesof which are open as indicated at 18,

I except that at suitable intervals supporting and strengthening ribs 19are provided. This leaves comparatively long and wide openings in which'theltuyere irons, indicated in Fig. 7 and numbered 20, are placed.These tuyere' irons have discharge ports21 formed in them through whichair is disangle irons have openings formed in them corresponding withthe port 21. The,

tuyere ironsor plates illustrated in Fig. 7 7

my be made in varying lengths. They maybe made quite short and. theremay be a large. number of them or ,they maybe jmade longer and of acorrespondingly less number. Since they are inlarge meas ure protectedby being seated within the refractoly housing 17 .itfollows that theywill notreadily burn out and if any. of them should burn out it is asimple matter to replace the burned out eiement or elements.

Thetsame thing is true with respect to the bricks illustrated in Fig. 6.Any one of these bricks" may be replaced without dis turbing any of theothers, it being only n'ecessary to lift thefburned out bricli from itsplace and to set another brick in itsplace.

In Fig. '5 I have illustrated upstanding portions 12 constituting alimiting meansfor limiting the inward movement of the plate of Fig.7 atthe lower edge of said plate and I have indicated downwardly extendingribs 17 for limiting inward movement of said plate at the upper edge'ofthe said plate. n

It is torbe understoodthat the invention isnot limited tohtheprecise'c'onstrliction set forth but that it includes within its purviewwhatever changes fairly come within eitlier theterms or the spirit ofthe appendedclaims. .4 Having described 'niy invention what -I clairnis? 1. A furnace of the character'describ ed comprising a masonry basehaving aplurality of open ducts formed thereim means for supplying airto said ducts fromthe extenor of the furnace, and refractory hOllS1- Iings of inverted U shape in cross section.

having laterally open ports in their" side walls whih housings .spansaid ducts and are continuous throughout the length said ducts, theedgesof said housings beingseat ed along the edges of said du'cts. i

" 2. A furnace: of the character described comprising base. having,aplurality of open top ducts 'formed therein; means for supplying air tosaid ducts firom'the e x'te f rior of the furnace and a pluralityofhollow fire-brick of inverted U shape spanning said ducts andcontinuous throughout the length thereof; said bricks being placed together end',' to end to constitutehousings over said ducts, said brickshavinglaterally,

open ports in their side walls. a. 4 v V 3. A structure as ,r'ec'it'e'din claim F 2 wherein'saidbrick have inclined tops:

4. A structure as recited claim-2 where in the base is recessed alongsaid duets for the reception of the lower edgesof said brick.

5..A furnaceof the character described comprising a base of masonryhavingFa plu rality of open top ducts formed therein, means forsupplying air to said ducts" from the exterior of said'base, housingsdisposed ovLer said ducts and extend ng longitudi-- nally the'rofinan'imbr'oken line, said housings being formed of refractory material andhaving openingsiformed in. their side walls and metallic tuyere plateseated in' said openings. i

In testimony whereof hreilntofaifixfmv signature.

ALONZO litiEN *rrio A s.

